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ETA: This post would be appropriate without it, just as posts that aren't appropriate without it aren't appropriate with it.

Invoking the word does nothing, for there is no power in the word, the power is in that to which the word applies.

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16 Rational toy buying

by [anonymous]

19th Oct 2011

2 min read

16

I have an 8-year-old sister who is very interested in science. The school she attends (in rural Indiana) takes the mantra of "teaching to the test" to a whole new level; my sister has already come home from school many days crying and stressed over fear that she won't pass her state's proficiency tests (which are 5+ months away). They are underfunded and the science curriculum is what most of the (overtly religious) teachers are undertrained in, and so science is essentially not addressed. My sister has about an order of magnitude more homework on cursive writing than on anything related to science.

I want to purchase a gift for her for the holidays this year (the occasion doesn't matter, but it's a time when I'll actually be home so I can give her the gift and play with her / explain how to use it / hopefully help her start thinking about some things). I'm willing to consider age-appropriate ideas across several price ranges, but I want to think of something that will deliver a lot of utility: i.e. it should be compelling enough that an 8-year-old will actually like using it and there should be at least some evidence that she will benefit from it.

I've considered things like the EDUbuntu computers that come with lots of educational software, but actually buying one seems to be not straightforward. Is the best thing to buy a cheap netbook at then install EDUbuntu myself? Is a netbook too much for an 8-year-old? I'm mostly focused on things that will help her be proficient with computers and potentially help her develop a more sophisticated interest in them as she grows up. The Lego Mindstorm robotics stuff also crossed my mind.

Does anyone have experience with this / know of resources for making a good investment? Or am I way over-thinking this and just some regular Legos or art supplies are going to do essentially just as much good?

Added 02/25/2012

Much of the advice was very helpful. I ultimately found out that my young sister was interested in "mixing chemicals together because it looked cool." An item that I found which looked like a good way to bridge the gap between her more girly interests and her interest in chemistry was Perfume Science from Thames and Kosmos. I also purchased a variety kit from Snap Circuits. She loved both items and we spent a good bit of time playing with them during my trip home to see my family. We made several different kinds of perfume and also did some activities that helped explain how different extracts have been acquired throughout human history for their smells. Ultimately, my sister made a science fair project (something which surprised my parents a lot) based around one of the activities in the perfume science booklet, and she won second place.

I was very happy with both my decision to ask this question on LessWrong (despite the title of the post, which seems to seethingly annoy many LWers) and my purchase decisions. I used the website Fat Brain Toys to purchase the items and everything arrived without a problem. That site seemed to also have a reasonably good selection for more educationally oriented toys across several ages, and with useful customer reviews.

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[-]lessdazed13y200

There's that word again...

ETA: This post would be appropriate without it, just as posts that aren't appropriate without it aren't appropriate with it.

Invoking the word does nothing, for there is no power in the word, the power is in that to which the word applies.

[-]byrnema13y170

I would recommend a science encyclopedia, a single but large book with approximately 1-2 pages on a huge variety of topics. The reason I recommend this is because a person can develop a relationship with a hard copy book they can't develop with an internet encyclopedia (my daughter's favorite page is the one on the sun, and she can rattle off, 'a ball of burning hot gases...' from memory) and one can flip through the pages looking for something that looks interesting to them -- this is self-guided education at its best.

Another advantage of the encyclopedia is that it much more likely you will read about a topic you wouldn't have guessed you were interested in due to a particularly catching photograph (for example, about spiders) and it feels far more safe to surreptitiously or casually look up topics one might be uncomfortable about -- that is, without making a very strong commitment that that is something you want to read about. While looking up certain topics online requires a definitive decision (you don't accidentally end up at a site about the onset of puberty) and is (unfortunately) likely to encourage Google to give discomfiting or indiscreet ads, turning pages in your own Encyclopedia is entirely innocent. (It's your book, after all.)

My daughter's book has a page on religion (and it's on the surface a perfectly reasonable and unoffensive description, but I expect it will inevitably sink in that each culture and time in history has it's own religion...) and while our particular encyclopedia doesn't have a page on evolution, there are plenty of good pages on biology and the different kingdoms. I feel that each page is interesting enough that as my daughter spends time with her encyclopedia, she would be developing a fairly broad -- and occasionally detailed -- education in science.

[-]rocurley13y40

In particular, the DK Science Encyclopedia was my most prized possession when I was about that age. I strongly recommend it.

[-]Emile13y20

Seconded - during most of my childhood/teenagerhood, I had a big encyclopediaish dictionary with plenty of illustrations on my desk; browsing it was a good way of procrastinating. One can find worse!

[-]buybuydandavis13y00

Thirded. Sort of.

I had an encyclopedia while growing up, which gave the ability to address an intellectual interest on a topic, and just browse and see interesting things too. I read a lot of that. I don't know that kids get a lot of encouragement to read non fiction.

I like your impulse to physicality. There's something to be said for a book as a fixed object that you have a relationship with. You get a sense of completion, advancement, and accumulation that way. I don't know that it has to be a physical object, however, just something with object permanence. Khan Academy might be an alternative. A growing collection of knowledge, which will display to you your growing body of knowledge. I'm sure I would have liked that as a kid.

Some basic tools and a pile of things that are kind of broken? I do think there is something to just taking physical things apart and putting them back together. Getting acquainted with the idea of mechanism. How about a kit to build something? A go cart?

I like the go cart better than even the encyclopedia for the physicality of it. Get her something where she thinks without words. I think that's important, and increasingly missing in the industrialized world.

[-]Dr_Manhattan13y20

There are many of these of varying quality. Anything you can recommend?

[-]byrnema13y20

No, I would just recommend that it is at the child's reading level, rather than above, since a higher level can be intimidating. Encyclopedia's are inexpensive and it is better to just purchase another one as a child gets older. This encyclopedia I'm speaking of is already narrowed down to a child's science encyclopedia, so my feeling is that any one of them would be a good one. Lots of attractive photos, of course, and a broad variety of topics.

[-]MinibearRex13y00

I had several growing up, and really loved them. One of them (my first) I believe was called the "I Wonder Why Encyclopedia". I looked on Amazon for it, and it appears to be a rather popular title. I would be inclined towards just going to a bookstore and investigating their selection.

[-]Incorrect13y10

Why would you be uncomfortable when you can just enable private browsing mode and look it up when you are alone?

[-][anonymous]13y160

We are one step closer to the glorious time when a thread titled "Most rational choice of footwear" will appear.

I'm not trying to saying it was wrong to ask what the best educational gift for your little sister was, but that the word "rational" really didn't need to be in the title. :)

[-]Raemon13y40

Hey, you gotta have rationalist footwear to play rationalist one-foot!

[-][anonymous]13y20

I think it's easy to be duped into buying suboptimal toys, especially around the holidays. I was hoping for people to offer tips on the general psychology of children learning science at this age, so that those tips could be collected into a strategy for making a systematic and principled purchase decision. I can supply the details about my sister, but I don't know how to make sense of those details as applied to buying a toy to elicit a specific effect. I really think that 'rational toy buying' is appropriate. I was inspired by this post and was hoping to bring about a discussion that mirrored that but for purchasing educational toys. Lots of very useful advice and suggestions have been given, but my post fell short of my goal. Either way, I think my choice of title was relevant. I think it's very odd that so many LWers rapidly point out superfluous uses of "rational". I should go around to posts and point out superfluous pointings out of superfluous uses of "rational."

[-][anonymous]13y00

Kuribo's Shoe is the most rational choice of footwear. THE SHOE IS CIVILIZATION!

[-]Manfred13y130

If she doesn't already have something like it, I'd recommend a big box of legos or K'nex (Approved by My Childhood).

Depending on her level, various popular "The Science Of" books could be up her alley, or one of the "The Way Things Work" books.

Ah, I almost forgot! The Klutz books! The Klutz Explorabook was pretty awesome, and they've got some other good ones too.

[-]JoshuaZ13y80

"The Way Things Work" books.

Oh yeah, I had that book when I was that age. Absolutely awesome. The mammoths everywhere were great although I think I really only appreciated them when I got older.

[-]Luke_A_Somers13y60

BUT! Be careful not to get the utterly awful "How Stuff Works" book (or more than one?). They're age-appropriate to a 2 or 3 year old. More superficial than Richard Scarry's "What do People Do All Day?", which though surprisingly detailed is still around 5-year-old territory.

[-]Hansenista13y30

"The Way Things Work" books.

Seconded (or thirded). One of my favorite books as a child as well; it was one of my first thoughts on reading the original post.

[-][anonymous]13y10

Thanks, guys. I had not heard of these books. I will look into them.

[-]Pavitra13y10

Legos are a pretty important staple; you definitely want to cover the basics before going for the fancy stuff. Also, I recommend avoiding the lego sets that come with instructions and special parts for making specific things; stick to buckets of bricks and let the kids freely generalize.

[-]amcknight13y00

I agree, but you also want some fancy pieces that you usually only find in sets. Having a couple of fire pieces from dragons and gears from a mediocre car set made lego twice as awesome!

[-]Shmi13y110

An 8-year-old will have no trouble with computers, but before buying one, figure out what she likes / is naturally good at. Maybe browsing sites like this will give you an idea for a gift (a microscope? a human body anatomy doll? a talking globe? a physics workshop science kit?).

Also, it seems like the best gift you can give her is taking her out of a school like that. You may have to brainstorm some creative alternatives, have some serious talk with your parents and likely spend more money than you intended.

[-]JoshuaZ13y90

Adding as separate comment to my earlier remarks because it isn't a traditional gift (and because I didn't actually think of it until after I posted my earlier comment): consider getting her a tutor. I don't know what your budget is, but one of the things that could help her the most is regular tutoring in math and science. Unfortunately, the obvious people to use for this are grad students and there are unlikely to be many easily accessible grad students in rural locations.

In general, if the science curriculum is poor the math curriculum likely also suffers, and in the long-run that may matter more since so much serious science depends on math. One thing to do is to get her interesting math to do. However, I don't know anything specifically aimed at that young an age range. One thing you definitely can do that doesn't take any money (and thus doesn't fall into the gift thing but may be a good idea) is give her interesting puzzles to solve that challenge her. This may require careful calibration. But at that age, doing something like simply explaining ideas like primer numbers can cause kids to go off and play on their own with the ideas. There's a lot of evidence that females are more vulnerable to math anxiety than males and that this is highly culturally mediated. See [e.g. this study (pdf). This is likely to be even more severe in a conservative, rural environment. So taking steps to help get her to enjoy math and understand that it is ok and even good for girls to like math may be helpful.

[-][anonymous]13y20

I like this idea and if I lived closer I would definitely do this myself (being a grad student and all). There is a serious dearth of qualified tutors in her area, and I have tried to get my parents to sort of tutor her with the Khan academy website, but I don't know if they use it.

[-]PuyaSharif13y80

When I was eight or nine i got one of those electricity/magnetism experiment kits. Boy, did I love that kit! I did that motor, electric bell and electromagnet experiment over and over again for maybe a year and then moved on to building my own electronic stuff from components I found tearing old TV's and radios apart. I soon had a little club at home teaching my friends!

Some years ago when my cousin just had turned nine I got him a kit and hoped to see him become as interested in electronics as I was in his age. But he hardly opened the box, and when I came to visit a year later that kit was long gone and forgotten. It simply could not stand the competition against the video games and toy guns.

I don't want to demotivate you with this story. Just want to say that stimulating a kid towards some interest is much more than buying a set of object for them. The key is the time you spend and how you spend it. Make it a step by step project. Ask her; maybe there are things among your alternatives that are more interesting to her than other. Followup and communicate. Visit museums etc..

[-]lukeprog13y70

Children should have netbooks at age 5, and never learn cursive.

[-]tenshiko13y50

I happen to like writing in cursive. I acknowledge potential bias based on socialization blah blah blah I was raised that way blah blah blah, but I genuinely find cursive more pleasant to write than print due to the lack of having to torturously pick up my pencil for every single new letter.

Furthermore, your proposal contains no consideration whatsoever on the effect of backlit screens on eye function.

[-]Raemon13y50

I'm torn about this. I'm not sure if I have an above averagedly crippling internet addiction or if other people here just don't consider it as problematic, but I don't think a personal computer at age 5 would have helped me.

Cursive is an utter waste of time though.

[-][anonymous]13y20

Wouldn't say an utter waste of time. Cursive capital letters get used in higher math occasionally, e.g. for families of sets. If you don't remember how to write them, you end up having to re-learn them sooner or later. Being able to write a perfect cursive G on a chalkboard is the mark of a great professor.

Waste of time for most people, though.

Edit: soooo many people are taking this as a serious argument in favor of learning cursive (and getting massive karma for poking holes in it)! That'll teach me to make frivolous comments.

[-]Raemon13y90

Anyone who needs to learn to write a cursive G can spend a week learning it in their higher math class, rather than spending two years of their life in elementary school.

[-]Vaniver13y60

Being able to write a perfect cursive G on a chalkboard is the mark of a great professor.

Here I thought being a great professor was about educating students effectively, not chalkboard tricks.

[-]jefftk13y20

If I'm trying to evaluate professors, it's a lot easier to see how well they write "G" than how well they educate.

[-][anonymous]13y00

Well, first of all, being a great professor has nothing to do with educating students effectively, it's all about research. Whether that's a good thing or not is a different argument.

But to take your argument at face value, chalkboard tricks can help you be an effective teacher. I think a professor teaching math without writing anything at all (and without slide shows or other visual aids) would be less than 50% as effective as normal, even if everything else was perfect, and I've seen teachers whose boardwork is sufficiently terrible that they may as well not write anything. Writing on a blackboard requires quite a few "chalkboard tricks", though a cursive G probably wouldn't be one of the more common ones. It is important, however, to cultivate a handwriting in which "z" and "2", "t" and "+", "w" and omega, "l" and "1", etc. are easily distinguishable.

Chalkboard tricks do not a great professor make. But I would expect that the correlation is quite high, considering the potential benefits.

[-]Username13y00

I've only taken a half-dozen college-level math courses but I don't think I've seen any cursive letters yet. If we were going to teach kids cursive in case they one day take higher-level math, we should also be sure to teach them the Greek letters because those are used all the time. Of course the vast majority of people don't need to, don't want to, and won't ever take higher level math, so I'd say that teaching kids cursive is an utter waste of time. The time spent teaching cursive could be put to so much better use (e.g., more time devoted to science instruction), and while it's a bit awkward to learn to write new letters at a later age, I much prefer it to the endless cursive drills.

[-]Desrtopa13y20

Keep in mind that most kids are practically illiterate at the age of five, which makes the usefulness of a netbook sharply limited.

[-]lukeprog13y10

They aren't illiterate in nations that care a bit more about their children's education. In Ukraine, for example, you must be able to write sentences and recite your multiplication tables up to 100 to be admitted into first grade.

[-]Normal_Anomaly13y40

recite your multiplication tables up to 100

You mean you have to know 97x98 and so forth? . . . Wow, I'm not qualified to be a Ukrainian first-grader.

[-]Desrtopa13y00

Do they have mandatory pre-first-grade education?

I was functionally illiterate at the age of five despite considerable parental investment in my education, and considering that I had achieved a twelfth grade reading level by third grade, it certainly wasn't for a lack of aptitude.

With sufficient training from an early age, I would not be surprised to hear that most five year olds can learn to write basic sentences, but I would be very surprised if most can be trained to follow written statements at the same conversational level they're capable of by that age.

[-]lessdazed13y40

I have an 8-year-old sister who is very interested in science.

What does this mean? She probably has preferences. It's not likely that she is equally interested in life and electronics, systems and processes, discovering and inventing.

[-]JoshuaZ13y70

Actually, at that age range it might be that diverse. My impression from working with children is that clear interests don't normally start forming until around 12 years old. Note that this is completely anecdotal.

[-][anonymous]13y50

Yes, her interests are extremely broad within basic science. She really has only just been exposed to science; it has never been a school subject for her until this year and the news I received from my parents was just that she came home very excited during the first week of school because she would get to learn science. In the time since, her interest is disappearing because of the factors I mentioned in the OP. My goal is to get gifts of a variety of styles so that hopefully at least a few end up helping her explore her own interests and decide what those interests are.

[-]lessdazed13y40

I will sort of repeat myself: I see people other optimizing on this thread, half recommending books and half recommending experiments and hands-on things.

It may appear that she is equally interested in every sort of thing, it may be that even if she isn't the best thing to do is to expose her to every sort of thing, but some people are more "book/theory" people and some people are more "build it/test it" science people, and that's OK.

I think anything given to her should be customized for her preferences, as best you can ascertain them.

[-][anonymous]13y00

I think my point is that I want to use the gifts to help both she and I to ascertain her scientific interests. I never enjoyed (and still don't) "gift stereotyping" because I like to explore new things that I had not considered. I think that's especially appropriate for a curious child.

In my current state of knowledge I could not put anything more than an uninformative prior on how interested she is in experiments vs. Legos vs. encyclopedias. I'm willing to try an assortment of these things to hopefully help her cultivate whatever her own specific interests are, but I don't want to buy a large number of items each of which has an unacceptably low probability of stimulating creative thought. It's fine if people post other-optimizing replies because I can disentangle that much of their reply and convert it into "useful potential domains to explore" rather than "your sister should have this specific object." It's more like brainstorming; which kinds of toys have some people had positive experiences with and/or know of actual studies that illustrate that they foster scientific learning? I don't want to reduce the amount of feedback just because some of it might be other-optimizing.

Perhaps a few months after the holidays, I'll be able to write a post similar to this one but regarding this educational toy experience. But before I can, I'm just looking for brainstorming/advice. I don't see why that is an issue worth nitpicking over its rational appropriateness. I think your comments are correct and insightful and unproductive.

[-]lessdazed13y20

It's fine if people post other-optimizing replies

I'm sorry, I haven't communicated clearly.

I agree it's fine if people post other-optimizing replies, and that it is good to do here. It's warned against in general because people tend to do it too much, even considering how very similar humans are to each other. That doesn't mean that it's bad, just that there is a reliable heuristic to place a weight on one side of the balance when others ask for advice.

The method of other optimizing breaks down the more individualized the relevant preferences are, and here I've been very willing to classify people as largely belonging to one or another group - I was trying to point out what there is to be learned from people other optimizing; it has made me think of what I hadn't previously, that people tend to either prefer their science in hands on or abstract book form, and that this is a very important thing to know.

But before I can, I'm just looking for brainstorming/advice. I don't see why that is an issue worth nitpicking over its rational appropriateness.

I think it is appropriate for people to say what they think benefited them and then look for patterns in their responses. That means that I do find it worth considering it's appropriateness, but I am judging it perfectly fine in this context.

Basically, other optimizing was meant to be descriptive rather than a slur. For this same sort of reason I criticized using "rational" in the title, because its use like that is a step towards making it a simple compliment rather than a meaty descriptive word.

[-]JoshuaZ13y40

Dawkins new book "The Magic of Reality" is a science book geared to children of varying ages. I have not read it myself so I can't evaluate it for this purpose but it may be worth looking into.

I'd recommend a chemistry set but unfortunately many modern chemistry sets contain little more than colored water. (This is only partially hyperbole.)

[-]pedanterrific13y60

Potential concern: carrying a book with "Richard Dawkins" written on the front in big letters into a school where most of the teachers are overtly religious is not a recipe for success. Trust me on this.

That said, it's getting very positive reviews and Dawkins is a pretty good writer in general.

[-][anonymous]13y60

I am personally interested in Dawkins' book, however my parents are also fairly religious and so I think it is already a stretch for them to foster my sister's interest in science. I was frankly surprised when they asked me for ideas for good science gifts. I think Dawkins' book might be pushing the envelope too far with them and would rather pick my battles more wisely.

[-]MinibearRex13y20

I'd recommend a chemistry set but unfortunately many modern chemistry sets contain little more than colored water. (This is only partially hyperbole.)

Many do. Some are significantly better. Look for reviews. About the only type of chemistry that's going to be available in those sets is single substitution (color change) reactions, but it was a fun start for me at that age.

[-][anonymous]13y30

Yes, her interests are extremely broad within basic science. She really has only just been exposed to science; it has never been a school subject for her until this year and the news I received from my parents was just that she came home very excited during the first week of school because she would get to learn science. In the time since, her interest is disappearing because of the factors I mentioned in the OP. My goal is to get gifts of a variety of styles so that hopefully at least a few end up helping her explore her own interests and decide what those interests are.

I can't help but be reminded of John Holt and the unschooling movement. He argues that children are naturally curious, and that given time and freedom they will develop their own strong interests; the role of a concerned parent or sibling is to provide opportunities for them to develop interests, and to facilitate whatever interests they develop by providing resources relevant to them.

It's really sad that schooling destroys children's curiosity (I don't believe that schools that emphasise the science curriculum are significantly better in this regard than the school your sister attends). Given that she does attend school, your idea of getting her gifts in a variety of styles to provide her with avenues to explore and develop interests is (imho) just the right thing to do. Some technical Lego, Meccano or a chemistry set would be a great gift with that end in mind, assuming your parents are willing to help supervise her when you can't.

[-][anonymous]13y30

Recreating this experiment to confirm universal gravitation would be awesome. Construction of the experimental apparatus should be well within an intelligent 8-year-old's abilities - all you need to provide/acquire is the idea and the more specialized equipment (e.g. lead weights). You can go shopping together for the more common stuff (nylon monofilament, etc.).

Finding a suitable location is probably the trickiest part, but the reward would be well worth it - this is a real scientific experiment, the Cavendish experiment, which wasn't carried out until after Newton's lifetime. It is also something that nobody ever does in school, because our schools are lame and boring.

[-]JoshuaZ13y80

The level of precision, patience, and understanding in that experiment would make me estimate a slightly higher age range than 8 years old for it. I would have guessed around 12 as the appropriate minimal age.

[-][anonymous]13y00

Yeah, you're probably right.

[-]lessdazed13y50

I love that write up for this:

Nineteen centuries elapsed between the death of Archimedes in 212 B.C. and the publication of Newton's Principia in 1687. Given the philosophical implications of Newton's theory, it's interesting to speculate what might have happened had Archimedes discovered the universal nature of gravitation. To do this, he would have had to suspect that attraction was universal, suggest an experiment to confirm this, and perform that experiment, with results validating the hypothesis. Here is information in Archimedes' possession which might have suggested the universality of gravitation.

The main problem with this experiment for an eight year old is that one has to leave the room when it operates. That's a big deal.

[-][anonymous]13y10

It occurs to me that you could probably build a box around it with a plastic window, to isolate it from air currents.

[-]lessdazed13y20

Now suppose you're crouching down in order to move the test masses, with your centre of gravity one metre from the closer test mass, and that you weigh 65 kg. Plugging these numbers into the calculator shows that your own gravitational attraction on the nearer end of the beam is 0.000147 dynes, 1.7 times as great as that of the test mass. Your actual influence on the motion of the balance arm is less, however, since what matters is the difference in force exerted on the masses at the two ends of the balance arm. Since your centre of gravity is more distant than the test masses, the difference is less.

Let's work it out. Assume the centres of gravity of the two masses on the balance arm are 25 cm apart, and that you're crouching so the arm makes a 45° angle with your centre of gravity, one metre from the centre of the arm. The nearer mass is then 17.68 cm closer than the more distant one and the difference in gravitational attraction (or tidal force) on the two masses is the difference in attraction on a mass 91.16 cm distant and one 108.84 cm away. The calculator gives the attraction on the near end of the arm as 0.0001764 dynes and the far end as 0.0001238 dyne, with a difference of 0.0000527 dynes. Now recall that the force exerted by the test mass was 0.000085 dynes, only 1.6 times as large, so even taking into account the reduced tidal influence due to your greater distance, the force you exert on the balance cannot be neglected. This makes it essential to remotely monitor the experiment so your own mass doesn't disrupt it.

In practice, air currents due to your motion and resulting from convection driven by your body's temperature being above room temperature may exert greater forces on the balance arm than the gravitational field generated by your mass. In any case, it's best to let the experiment evolve on its own, observed from elsewhere.

[-][anonymous]13y00

That's what I deserve for not rereading the page after a decade, sigh.

[-]CronoDAS13y20

Fourmilab's version is bogus... given the masses involved, a calculation using f = GmM/r^2 shows that it should take a lot longer for the moving mass to reach the test mass than it does in the video. The most likely explanations for what is seen in Fourmilab's video are static electricity or outright fraud. (Incidentally, my father actually did build a working Cavendish experiment in our basement; it uses much larger fixed masses and a thinner wire, and it does indeed move much more slowly. It turned out to be very difficult to get it to work; the effects of ordinary air currents tend to overwhelm the gravitational attraction.)

[-][anonymous]13y10

Static electricity was mentioned:

As long as we made sure none of the objects we were experimenting with were magnetic or electrically charged (easily arranged, assuming they are conductive, simply by bringing them into contact so all excess charges equilibrate)

But you're right, I would consider it much more convincing if the experiment were set up so that everything was connected by conductors.

The other thing is that in the video, the bar is initially nearly perpendicular to the external masses. In this configuration, not only are the bar's masses far from the external masses, but the torques are almost balanced. I don't see any mention of this.

The video appears to indicate that it takes 3 minutes for the bar to rotate around and make contact with the external masses. I wrote a quick sketch of a program to figure out how long it should take, and I got over 3 hours. Specifically, I used the favorable assumptions that the foam bar is massless, that the setup is frictionless, and I calculated what would happen with one external mass of 740g and an initial separation of 17 cm, until the separation decreased to 2 cm. The initial separation isn't clearly stated anywhere - there is a vague mention of "at the 14 cm distance when the beam is at the midpoint between the masses". The bar diameter is clearly given as 30 cm, and I believe I'm getting the basic trig right when I calculate that an angle of 70 degrees would result in a 17 cm separation. Finally, I'm considering only one bar mass and one external mass (utterly neglecting the near-symmetrical torque is highly favorable, producing a time estimate that will be shorter than reality) and because I didn't want to write the trig, I'm working with linear movement in free space, instead of the actual rotation. (I used Boost.Units to ensure that I didn't screw up my math even further than these simplifications.)

I agree - something is extremely fishy here.

[-][anonymous]13y30

Showing my work:

C:\Temp>type meow.cpp
#include <iostream>
#include <ostream>
#include <boost/units/io.hpp>
#include <boost/units/pow.hpp>
#include <boost/units/quantity.hpp>
#include <boost/units/systems/si.hpp>
#include <boost/units/systems/si/prefixes.hpp>
#include <boost/units/systems/si/codata/universal_constants.hpp>
using namespace std;
using namespace boost::units;
using namespace boost::units::si;
using boost::units::si::constants::codata::G;

typedef quantity<boost::units::si::time> quantity_time;

int main() {
    const quantity<mass> external_mass(740 * kilograms / kilo);

    quantity<length> remaining_length(17 * centi * meters);

    const quantity<length> final_length(2 * centi * meters);

    quantity_time elapsed_time;

    quantity<velocity> total_velocity;

    while (remaining_length > final_length) {
        const quantity_time t(1 * second);

        const quantity<acceleration> a(G * external_mass / pow<2>(remaining_length));

        const quantity<length> l = total_velocity * t + 0.5 * a * pow<2>(t);

        elapsed_time += t;
        remaining_length -= l;
        total_velocity += a * t;
    }

    cout << elapsed_time << endl;
    cout << total_velocity << endl;
}

C:\Temp>g++ -Wall -Wextra meow.cpp -o meow.exe && meow
10882 s
6.6012e-005 m s^-1

The final velocity is about 9 inches per hour.

(It would be quite possible to modify this to do a fully "realistic" simulation, with the two pairs of masses and the rotation. That's more work than I want to do at 1 AM, though.)

[-]see13y20

Since anything else I'd suggest has been suggested . . .

A Snap Circuits kit. That's the high-end model that's linked; there are less expensive ones.

[-]Luke_A_Somers13y20

I'd buy her a book on a random topic that goes in depth, while maintaining age level. I got a lot more of a kick out of depth than breadth when I was a kid.

Technics lego are… well, I never made anything out of them that really took advantage of the mechanical elements, mainly because I didn't have the motor. Making a car that runs if you turn a wheel… well, you need to track it, and then you're basically pushing it along.

[-]NancyLebovitz13y10

Tentatively offered, but it might make sense to teach her about self-experimentation. I was thinking especially about cursive-- you can improve much faster if you think about what you want to change, develop an idea about what might change it, and then see whether your idea works.

I don't know about her, but when I was a kid, I was given the impression that you repeat what you're doing a lot, and then a miracle happens and you improve. This can happen, but it's more likely if you're doing something you're interested in. Even then, conscious experimentation is probably more efficient.

I agree that cursive is a waste of time. I'm a calligrapher, and it took me doing calligraphy to realize that (aside from any other issues), I hadn't liked cursive because it's ugly and unclear. Also, if you want to do it, it's easier if you understand the letter forms behind those loops. If you want pretty handwriting, italic is better.

Could it make sense for your sister to read this thread?

[-]lessdazed13y10

I recommend something, if it exists, at her reading level on Fermi estimates. Those exhibit the power of thought without using a level of precision that is too much for someone her age.

[-]EphemeralNight13y00

Legos

I played with both Legos and K'nex as a kid and I would strongly recommend the latter over the former if you're looking for something that's mentally stimulating. I still have all my K'nex; I sold all my Legos at garage sales years ago.

[-][anonymous]13y00

Yes, her interests are extremely broad within basic science. She really has only just been exposed to science; it has never been a school subject for her until this year and the news I received from my parents was just that she came home very excited during the first week of school because she would get to learn science. In the time since, her interest is disappearing because of the factors I mentioned in the OP. My goal is to get gifts of a variety of styles so that hopefully at least a few end up helping her explore her own interests and decide what those interests are.

I can't help but be reminded of John Holt(http://en.wikipedia.org/wiki/John_Holt_(educator)#From_Homeschooling_to_Unschooling) and the unschooling movement. He argues that children are naturally curious, and that given time and freedom they will develop their own strong interests; the role of a concerned parent (or sibling) is to provide opportunities for them to develop interests, and facilitating whatever interests they develop (however they originate) by providing resources relevant to that.

It's really sad that schooling destroys children's curiosity (I don't believe that schools that emphasise the science curriculum are significantly better than the school your sister attends). Given that she does attend school, your idea of getting her gifts in a variety of styles to provide her with avenues to explore and develop interests is (imho) just the right thing to do. Some technical Lego, Meccano or a Chemistry set would be a great gift with that end in mind, assuming your parents are willing to help supervise her when you can't.

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[-]Emile13y00

Does anyone have experience with this / know of resources for making a good investment? Or am I way over-thinking this and just some regular Legos or art supplies are going to do essentially just as much good?

I bought some sciency toys for my little brother (he was probably around the same age), like a kit for making crystals etc. - but that didn't get nearly as played with as regular Legos. Lego Technic are probably a good compromise towards Mindstorm (I get the impression those would be a bit complicated for an 8-year-old), though as a kif I remember having more fun with regular Legos than with Technic (yes, now I could build neater stuff with them, but a kid may be less likely to do so spontaneously).

I would rather have my kid play with Legos than play with a computer, even an EDUbuntu computer, but I don't know how well grounded that gut feeling is now (my kid is way too small for me to worry about that now). I'll have to research it more in depth eventually.

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